1. Field of the Invention
The present invention relates to a call acceptance control method, mobile communication system and base station device employed in mobile communications in which multiple access is effected with shared wireless resources.
2. Related Background Art
In a mobile communication system comprising a wireless base station and a plurality of mobile stations, data communication (transmission/reception) is performed by wireless communication circuits between the base station and the mobile stations. Circuit switching systems and packet switching systems are examples of switching systems employed in such data transmission/reception.
A circuit switching system is a system in which fixed wireless resources are occupied in respect of communication with a user connected by a circuit switching call, irrespective of whether or not data is transferred. A certain rate of call loss occurs in this system, but it has the advantage that data transfer delay does not occur, so it is suited to a communication service with a high degree of real-time character, such as voice communication.
In contrast, the packet switching system is a system wherein the data that is transferred in respect of a user connected by a packet call is constituted by small data units called packets; in this system, the data is transferred in packet units and wireless resources are only occupied as necessary. In this system, a certain degree of data transfer delay occurs, but wireless resources are allocated at each time-point in accordance with the degree of necessity of transmission/reception of data from a plurality of call sources (mobile stations). It therefore has the advantage that it enables efficient use of shared wireless resources in a plurality of communications and is suited for communication services of a low degree of real-time character, such as communications wherein the amount of data transferred changes irregularly and/or communications having a burst character. Such packet switching systems are employed in data communication on Internet connections or for transfer of control signals.